Why Lists of Dictionaries? Why PLOD?

These data stores can include lists of collections, and each collection can have many attributes/values. In Python, these are often internally represented as a list containing dictionaries. For example, if you needed to represent a list of fruits available for purchase:

One could, of course, pass such a structure into a SQL database such as MySQL or PostgreSQL for manipulation. But that can be overkill for a small amount of temporary data, especially when the infrastructure requirements are light and response time is critical. In that case, manipulating such a list might make more sense to do in-memory within Python itself.

If it is simple enough, one could do so directly using Python. For example:

abundant_fruit = [f for f in fruits if f['qty']>5]

But, if the program you are writing does such manipulations regularly, and those manipulations are somewhat more complex, then PLOD might be worth using. To mimic the previous example, this time with PLOD: